Is it normal for my symptoms to almost disappear at 17 weeks?

Yes it is normal for your symptoms to go away during the second trimester. For me it was amazing compared to the 1st and 3rd, my 1st was nothing but morning sickness and my 3rd was exhausting and frustrating. Just frustrating because I was always tired and very uncomfortable. If your doctor is acting lazy I would suggest finding a new doctor, you don't need the sonogram machine to hear your babys heartbeat... my doctor used a a little stethascope machine that told him how fast my babys heartbeat was, I was also able to hear it at the same time so was my husband. So don't worry, your 2nd trimester should be a breeze and hopefully your doctor gets better at his job, laziness isn't part it. Good luck and best wishes!